/*
 *	MP3 huffman table selecting and bit counting
 *
 *	Copyright (c) 1999-2005 Takehiro TOMINAGA
 *	Copyright (c) 2002-2005 Gabriel Bouvigne
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* $Id: Takehiro.java,v 1.26 2011/05/24 20:48:06 kenchis Exp $ */

package net.sourceforge.lame.mp3;

import java.util.Arrays;


public class Takehiro {

  public static final int slen1_tab[] = {0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3,
      3, 3, 4, 4};
  public static final int slen2_tab[] = {0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1,
      2, 3, 2, 3};
  /**
   * *********************************************************************
   */

  private final static int huf_tbl_noESC[] = {1, 2, 5, 7, 7, 10, 10, 13, 13,
      13, 13, 13, 13, 13, 13};
  private static final int slen1_n[] = {1, 1, 1, 1, 8, 2, 2, 2, 4, 4, 4, 8,
      8, 8, 16, 16};
  private static final int slen2_n[] = {1, 2, 4, 8, 1, 2, 4, 8, 2, 4, 8, 2,
      4, 8, 4, 8};
  /**
   * number of bits used to encode scalefacs.
   * <p/>
   * 18*slen1_tab[i] + 18*slen2_tab[i]
   */
  private static final int scale_short[] = {0, 18, 36, 54, 54, 36, 54, 72,
      54, 72, 90, 72, 90, 108, 108, 126};
  /**
   * number of bits used to encode scalefacs.
   * <p/>
   * 17*slen1_tab[i] + 18*slen2_tab[i]
   */
  private static final int scale_mixed[] = {0, 18, 36, 54, 51, 35, 53, 71,
      52, 70, 88, 69, 87, 105, 104, 122};
  /**
   * number of bits used to encode scalefacs.
   * <p/>
   * 11*slen1_tab[i] + 10*slen2_tab[i]
   */
  private static final int scale_long[] = {0, 10, 20, 30, 33, 21, 31, 41, 32, 42,
      52, 43, 53, 63, 64, 74};
  /**
   * table of largest scalefactor values for MPEG2
   */
  private static final int max_range_sfac_tab[][] = {{15, 15, 7, 7},
      {15, 15, 7, 0}, {7, 3, 0, 0}, {15, 31, 31, 0},
      {7, 7, 7, 0}, {3, 3, 0, 0}};
  /*
   * Since no bands have been over-amplified, we can set scalefac_compress and
   * slen[] for the formatter
   */
  private static final int log2tab[] = {0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4,
      4, 4, 4, 4};
  QuantizePVT qupvt;
  private int subdv_table[][] = {{0, 0}, /* 0 bands */
      {0, 0}, /* 1 bands */
      {0, 0}, /* 2 bands */
      {0, 0}, /* 3 bands */
      {0, 0}, /* 4 bands */
      {0, 1}, /* 5 bands */
      {1, 1}, /* 6 bands */
      {1, 1}, /* 7 bands */
      {1, 2}, /* 8 bands */
      {2, 2}, /* 9 bands */
      {2, 3}, /* 10 bands */
      {2, 3}, /* 11 bands */
      {3, 4}, /* 12 bands */
      {3, 4}, /* 13 bands */
      {3, 4}, /* 14 bands */
      {4, 5}, /* 15 bands */
      {4, 5}, /* 16 bands */
      {4, 6}, /* 17 bands */
      {5, 6}, /* 18 bands */
      {5, 6}, /* 19 bands */
      {5, 7}, /* 20 bands */
      {6, 7}, /* 21 bands */
      {6, 7}, /* 22 bands */
  };

  /*************************************************************************/
	/* choose table */

  public final void setModules(QuantizePVT qupvt) {
    this.qupvt = qupvt;
  }

  /**
   * nonlinear quantization of xr More accurate formula than the ISO formula.
   * Takes into account the fact that we are quantizing xr . ix, but we want
   * ix^4/3 to be as close as possible to x^4/3. (taking the nearest int would
   * mean ix is as close as possible to xr, which is different.)
   * <p/>
   * From Segher Boessenkool <segher@eastsite.nl> 11/1999
   * <p/>
   * 09/2000: ASM code removed in favor of IEEE754 hack by Takehiro Tominaga.
   * If you need the ASM code, check CVS circa Aug 2000.
   * <p/>
   * 01/2004: Optimizations by Gabriel Bouvigne
   */
  private void quantize_lines_xrpow_01(int l, float istep, final float[] xr,
                                       int xrPos, int[] ix, int ixPos) {
    final float compareval0 = (1.0f - 0.4054f) / istep;

    assert (l > 0);
    l = l >> 1;
    while ((l--) != 0) {
      ix[ixPos++] = (compareval0 > xr[xrPos++]) ? 0 : 1;
      ix[ixPos++] = (compareval0 > xr[xrPos++]) ? 0 : 1;
    }
  }

  /**
   * XRPOW_FTOI is a macro to convert floats to ints.<BR>
   * if XRPOW_FTOI(x) = nearest_int(x), then QUANTFAC(x)=adj43asm[x]<BR>
   * ROUNDFAC= -0.0946<BR>
   * <p/>
   * if XRPOW_FTOI(x) = floor(x), then QUANTFAC(x)=asj43[x]<BR>
   * ROUNDFAC=0.4054<BR>
   * <p/>
   * Note: using floor() or (int) is extremely slow. On machines where the
   * TAKEHIRO_IEEE754_HACK code above does not work, it is worthwile to write
   * some ASM for XRPOW_FTOI().
   */
  private void quantize_lines_xrpow(int l, float istep, final float[] xr,
                                    int xrPos, int[] ix, int ixPos) {
    assert (l > 0);

    l = l >> 1;
    int remaining = l % 2;
    l = l >> 1;
    while (l-- != 0) {
      float x0, x1, x2, x3;
      int rx0, rx1, rx2, rx3;

      x0 = xr[xrPos++] * istep;
      x1 = xr[xrPos++] * istep;
      rx0 = (int) x0;
      x2 = xr[xrPos++] * istep;
      rx1 = (int) x1;
      x3 = xr[xrPos++] * istep;
      rx2 = (int) x2;
      x0 += qupvt.adj43[rx0];
      rx3 = (int) x3;
      x1 += qupvt.adj43[rx1];
      ix[ixPos++] = (int) x0;
      x2 += qupvt.adj43[rx2];
      ix[ixPos++] = (int) x1;
      x3 += qupvt.adj43[rx3];
      ix[ixPos++] = (int) x2;
      ix[ixPos++] = (int) x3;
    }
    if (remaining != 0) {
      float x0, x1;
      int rx0, rx1;

      x0 = xr[xrPos++] * istep;
      x1 = xr[xrPos++] * istep;
      rx0 = (int) x0;
      rx1 = (int) x1;
      x0 += qupvt.adj43[rx0];
      x1 += qupvt.adj43[rx1];
      ix[ixPos++] = (int) x0;
      ix[ixPos++] = (int) x1;
    }
  }

  /**
   * Quantization function This function will select which lines to quantize
   * and call the proper quantization function
   */
  private void quantize_xrpow(final float[] xp, int[] pi, float istep,
                              final GrInfo codInfo, final CalcNoiseData prevNoise) {
    /* quantize on xr^(3/4) instead of xr */
    int sfb;
    int sfbmax;
    int j = 0;
    boolean prev_data_use;
    int accumulate = 0;
    int accumulate01 = 0;

    int xpPos = 0;

    int[] iData = pi;
    int iDataPos = 0;
    int[] acc_iData = iData;
    int acc_iDataPos = 0;
    float[] acc_xp = xp;
    int acc_xpPos = 0;

		/*
		 * Reusing previously computed data does not seems to work if global
		 * gain is changed. Finding why it behaves this way would allow to use a
		 * cache of previously computed values (let's 10 cached values per sfb)
		 * that would probably provide a noticeable speedup
		 */
    prev_data_use = (prevNoise != null && (codInfo.global_gain == prevNoise.global_gain));

    if (codInfo.block_type == Encoder.SHORT_TYPE)
      sfbmax = 38;
    else
      sfbmax = 21;

    for (sfb = 0; sfb <= sfbmax; sfb++) {
      int step = -1;

      if (prev_data_use || codInfo.block_type == Encoder.NORM_TYPE) {
        step = codInfo.global_gain
            - ((codInfo.scalefac[sfb] + (codInfo.preflag != 0 ? qupvt.pretab[sfb]
            : 0)) << (codInfo.scalefac_scale + 1))
            - codInfo.subblock_gain[codInfo.window[sfb]] * 8;
      }
      assert (codInfo.width[sfb] >= 0);
      if (prev_data_use && (prevNoise.step[sfb] == step)) {
				/*
				 * do not recompute this part, but compute accumulated lines
				 */
        if (accumulate != 0) {
          quantize_lines_xrpow(accumulate, istep, acc_xp, acc_xpPos,
              acc_iData, acc_iDataPos);
          accumulate = 0;
        }
        if (accumulate01 != 0) {
          quantize_lines_xrpow_01(accumulate01, istep, acc_xp,
              acc_xpPos, acc_iData, acc_iDataPos);
          accumulate01 = 0;
        }
      } else { /* should compute this part */
        int l = codInfo.width[sfb];

        if ((j + codInfo.width[sfb]) > codInfo.max_nonzero_coeff) {
					/* do not compute upper zero part */
          int usefullsize;
          usefullsize = codInfo.max_nonzero_coeff - j + 1;
          Arrays.fill(pi, codInfo.max_nonzero_coeff, 576, 0);
          l = usefullsize;

          if (l < 0) {
            l = 0;
          }

					/* no need to compute higher sfb values */
          sfb = sfbmax + 1;
        }

				/* accumulate lines to quantize */
        if (0 == accumulate && 0 == accumulate01) {
          acc_iData = iData;
          acc_iDataPos = iDataPos;
          acc_xp = xp;
          acc_xpPos = xpPos;
        }
        if (prevNoise != null && prevNoise.sfb_count1 > 0
            && sfb >= prevNoise.sfb_count1
            && prevNoise.step[sfb] > 0
            && step >= prevNoise.step[sfb]) {

          if (accumulate != 0) {
            quantize_lines_xrpow(accumulate, istep, acc_xp,
                acc_xpPos, acc_iData, acc_iDataPos);
            accumulate = 0;
            acc_iData = iData;
            acc_iDataPos = iDataPos;
            acc_xp = xp;
            acc_xpPos = xpPos;
          }
          accumulate01 += l;
        } else {
          if (accumulate01 != 0) {
            quantize_lines_xrpow_01(accumulate01, istep, acc_xp,
                acc_xpPos, acc_iData, acc_iDataPos);
            accumulate01 = 0;
            acc_iData = iData;
            acc_iDataPos = iDataPos;
            acc_xp = xp;
            acc_xpPos = xpPos;
          }
          accumulate += l;
        }

        if (l <= 0) {
					/*
					 * rh: 20040215 may happen due to "prev_data_use"
					 * optimization
					 */
          if (accumulate01 != 0) {
            quantize_lines_xrpow_01(accumulate01, istep, acc_xp,
                acc_xpPos, acc_iData, acc_iDataPos);
            accumulate01 = 0;
          }
          if (accumulate != 0) {
            quantize_lines_xrpow(accumulate, istep, acc_xp,
                acc_xpPos, acc_iData, acc_iDataPos);
            accumulate = 0;
          }

          break; /* ends for-loop */
        }
      }
      if (sfb <= sfbmax) {
        iDataPos += codInfo.width[sfb];
        xpPos += codInfo.width[sfb];
        j += codInfo.width[sfb];
      }
    }
    if (accumulate != 0) { /* last data part */
      quantize_lines_xrpow(accumulate, istep, acc_xp, acc_xpPos,
          acc_iData, acc_iDataPos);
      accumulate = 0;
    }
    if (accumulate01 != 0) { /* last data part */
      quantize_lines_xrpow_01(accumulate01, istep, acc_xp, acc_xpPos,
          acc_iData, acc_iDataPos);
      accumulate01 = 0;
    }

  }

  /**
   * ix_max
   */
  private int ix_max(final int[] ix, int ixPos, final int endPos) {
    int max1 = 0, max2 = 0;

    do {
      final int x1 = ix[ixPos++];
      final int x2 = ix[ixPos++];
      if (max1 < x1)
        max1 = x1;

      if (max2 < x2)
        max2 = x2;
    } while (ixPos < endPos);
    if (max1 < max2)
      max1 = max2;
    return max1;
  }

  private int count_bit_ESC(final int[] ix, int ixPos, final int end, int t1,
                            final int t2, Bits s) {
		/* ESC-table is used */
    final int linbits = Tables.ht[t1].xlen * 65536 + Tables.ht[t2].xlen;
    int sum = 0, sum2;

    do {
      int x = ix[ixPos++];
      int y = ix[ixPos++];

      if (x != 0) {
        if (x > 14) {
          x = 15;
          sum += linbits;
        }
        x *= 16;
      }

      if (y != 0) {
        if (y > 14) {
          y = 15;
          sum += linbits;
        }
        x += y;
      }

      sum += Tables.largetbl[x];
    } while (ixPos < end);

    sum2 = sum & 0xffff;
    sum >>= 16;

    if (sum > sum2) {
      sum = sum2;
      t1 = t2;
    }

    s.bits += sum;
    return t1;
  }

  private int count_bit_noESC(final int[] ix, int ixPos, final int end, Bits s) {
		/* No ESC-words */
    int sum1 = 0;
    final int[] hlen1 = Tables.ht[1].hlen;

    do {
      final int x = ix[ixPos + 0] * 2 + ix[ixPos + 1];
      ixPos += 2;
      sum1 += hlen1[x];
    } while (ixPos < end);

    s.bits += sum1;
    return 1;
  }

  private int count_bit_noESC_from2(final int[] ix, int ixPos, final int end,
                                    int t1, Bits s) {
		/* No ESC-words */
    int sum = 0, sum2;
    final int xlen = Tables.ht[t1].xlen;
    final int[] hlen;
    if (t1 == 2)
      hlen = Tables.table23;
    else
      hlen = Tables.table56;

    do {
      final int x = ix[ixPos + 0] * xlen + ix[ixPos + 1];
      ixPos += 2;
      sum += hlen[x];
    } while (ixPos < end);

    sum2 = sum & 0xffff;
    sum >>= 16;

    if (sum > sum2) {
      sum = sum2;
      t1++;
    }

    s.bits += sum;
    return t1;
  }

  private int count_bit_noESC_from3(final int[] ix, int ixPos, final int end,
                                    int t1, Bits s) {
		/* No ESC-words */
    int sum1 = 0;
    int sum2 = 0;
    int sum3 = 0;
    final int xlen = Tables.ht[t1].xlen;
    final int[] hlen1 = Tables.ht[t1].hlen;
    final int[] hlen2 = Tables.ht[t1 + 1].hlen;
    final int[] hlen3 = Tables.ht[t1 + 2].hlen;

    do {
      final int x = ix[ixPos + 0] * xlen + ix[ixPos + 1];
      ixPos += 2;
      sum1 += hlen1[x];
      sum2 += hlen2[x];
      sum3 += hlen3[x];
    } while (ixPos < end);

    int t = t1;
    if (sum1 > sum2) {
      sum1 = sum2;
      t++;
    }
    if (sum1 > sum3) {
      sum1 = sum3;
      t = t1 + 2;
    }
    s.bits += sum1;

    return t;
  }

  /**
   * Choose the Huffman table that will encode ix[begin..end] with the fewest
   * bits.
   * <p/>
   * Note: This code contains knowledge about the sizes and characteristics of
   * the Huffman tables as defined in the IS (Table B.7), and will not work
   * with any arbitrary tables.
   */
  private int choose_table(final int[] ix, final int ixPos, final int endPos,
                           final Bits s) {
    int max = ix_max(ix, ixPos, endPos);

    switch (max) {
      case 0:
        return max;

      case 1:
        return count_bit_noESC(ix, ixPos, endPos, s);

      case 2:
      case 3:
        return count_bit_noESC_from2(ix, ixPos, endPos,
            huf_tbl_noESC[max - 1], s);

      case 4:
      case 5:
      case 6:
      case 7:
      case 8:
      case 9:
      case 10:
      case 11:
      case 12:
      case 13:
      case 14:
      case 15:
        return count_bit_noESC_from3(ix, ixPos, endPos,
            huf_tbl_noESC[max - 1], s);

      default:
			/* try tables with linbits */
        if (max > QuantizePVT.IXMAX_VAL) {
          s.bits = QuantizePVT.LARGE_BITS;
          return -1;
        }
        max -= 15;
        int choice2;
        for (choice2 = 24; choice2 < 32; choice2++) {
          if (Tables.ht[choice2].linmax >= max) {
            break;
          }
        }
        int choice;
        for (choice = choice2 - 8; choice < 24; choice++) {
          if (Tables.ht[choice].linmax >= max) {
            break;
          }
        }
        return count_bit_ESC(ix, ixPos, endPos, choice, choice2, s);
    }
  }

  /**
   * count_bit
   */
  public int noquant_count_bits(final LameInternalFlags gfc,
                                final GrInfo gi, CalcNoiseData prev_noise) {
    final int[] ix = gi.l3_enc;

    int i = Math.min(576, ((gi.max_nonzero_coeff + 2) >> 1) << 1);

    if (prev_noise != null)
      prev_noise.sfb_count1 = 0;

		/* Determine count1 region */
    for (; i > 1; i -= 2)
      if ((ix[i - 1] | ix[i - 2]) != 0)
        break;
    gi.count1 = i;

		/* Determines the number of bits to encode the quadruples. */
    int a1 = 0;
    int a2 = 0;
    for (; i > 3; i -= 4) {
      int p;
			/* hack to check if all values <= 1 */
      if ((((long) ix[i - 1] | (long) ix[i - 2] | (long) ix[i - 3] | (long) ix[i - 4]) & 0xffffffffL) > 1L)
        break;

      p = ((ix[i - 4] * 2 + ix[i - 3]) * 2 + ix[i - 2]) * 2 + ix[i - 1];
      a1 += Tables.t32l[p];
      a2 += Tables.t33l[p];
    }

    int bits = a1;
    gi.count1table_select = 0;
    if (a1 > a2) {
      bits = a2;
      gi.count1table_select = 1;
    }

    gi.count1bits = bits;
    gi.big_values = i;
    if (i == 0)
      return bits;

    if (gi.block_type == Encoder.SHORT_TYPE) {
      a1 = 3 * gfc.scalefac_band.s[3];
      if (a1 > gi.big_values)
        a1 = gi.big_values;
      a2 = gi.big_values;

    } else if (gi.block_type == Encoder.NORM_TYPE) {
      assert (i <= 576); /* bv_scf has 576 entries (0..575) */
      a1 = gi.region0_count = gfc.bv_scf[i - 2];
      a2 = gi.region1_count = gfc.bv_scf[i - 1];

      assert (a1 + a2 + 2 < Encoder.SBPSY_l);
      a2 = gfc.scalefac_band.l[a1 + a2 + 2];
      a1 = gfc.scalefac_band.l[a1 + 1];
      if (a2 < i) {
        Bits bi = new Bits(bits);
        gi.table_select[2] = choose_table(ix, a2, i, bi);
        bits = bi.bits;
      }
    } else {
      gi.region0_count = 7;
			/* gi.region1_count = SBPSY_l - 7 - 1; */
      gi.region1_count = Encoder.SBMAX_l - 1 - 7 - 1;
      a1 = gfc.scalefac_band.l[7 + 1];
      a2 = i;
      if (a1 > a2) {
        a1 = a2;
      }
    }

		/* have to allow for the case when bigvalues < region0 < region1 */
		/* (and region0, region1 are ignored) */
    a1 = Math.min(a1, i);
    a2 = Math.min(a2, i);

    assert (a1 >= 0);
    assert (a2 >= 0);

		/* Count the number of bits necessary to code the bigvalues region. */
    if (0 < a1) {
      Bits bi = new Bits(bits);
      gi.table_select[0] = choose_table(ix, 0, a1, bi);
      bits = bi.bits;
    }
    if (a1 < a2) {
      Bits bi = new Bits(bits);
      gi.table_select[1] = choose_table(ix, a1, a2, bi);
      bits = bi.bits;
    }
    if (gfc.use_best_huffman == 2) {
      gi.part2_3_length = bits;
      best_huffman_divide(gfc, gi);
      bits = gi.part2_3_length;
    }

    if (prev_noise != null) {
      if (gi.block_type == Encoder.NORM_TYPE) {
        int sfb = 0;
        while (gfc.scalefac_band.l[sfb] < gi.big_values) {
          sfb++;
        }
        prev_noise.sfb_count1 = sfb;
      }
    }

    return bits;
  }

  public int count_bits(final LameInternalFlags gfc, final float[] xr,
                        final GrInfo gi, CalcNoiseData prev_noise) {
    final int[] ix = gi.l3_enc;

		/* since quantize_xrpow uses table lookup, we need to check this first: */
    final float w = (QuantizePVT.IXMAX_VAL) / qupvt.IPOW20(gi.global_gain);

    if (gi.xrpow_max > w)
      return QuantizePVT.LARGE_BITS;

    quantize_xrpow(xr, ix, qupvt.IPOW20(gi.global_gain), gi, prev_noise);

    if ((gfc.substep_shaping & 2) != 0) {
      int j = 0;
			/* 0.634521682242439 = 0.5946*2**(.5*0.1875) */
      final int gain = gi.global_gain + gi.scalefac_scale;
      final float roundfac = 0.634521682242439f / qupvt.IPOW20(gain);
      for (int sfb = 0; sfb < gi.sfbmax; sfb++) {
        final int width = gi.width[sfb];
        assert (width >= 0);
        if (0 == gfc.pseudohalf[sfb]) {
          j += width;
        } else {
          int k;
          for (k = j, j += width; k < j; ++k) {
            ix[k] = (xr[k] >= roundfac) ? ix[k] : 0;
          }
        }
      }
    }
    return noquant_count_bits(gfc, gi, prev_noise);
  }

  /**
   * re-calculate the best scalefac_compress using scfsi the saved bits are
   * kept in the bit reservoir.
   */
  private void recalc_divide_init(final LameInternalFlags gfc,
                                  final GrInfo cod_info, final int[] ix, int r01_bits[],
                                  int r01_div[], int r0_tbl[], int r1_tbl[]) {
    int bigv = cod_info.big_values;

    for (int r0 = 0; r0 <= 7 + 15; r0++) {
      r01_bits[r0] = QuantizePVT.LARGE_BITS;
    }

    for (int r0 = 0; r0 < 16; r0++) {
      final int a1 = gfc.scalefac_band.l[r0 + 1];
      if (a1 >= bigv)
        break;
      int r0bits = 0;
      Bits bi = new Bits(r0bits);
      int r0t = choose_table(ix, 0, a1, bi);
      r0bits = bi.bits;

      for (int r1 = 0; r1 < 8; r1++) {
        final int a2 = gfc.scalefac_band.l[r0 + r1 + 2];
        if (a2 >= bigv)
          break;

        int bits = r0bits;
        bi = new Bits(bits);
        int r1t = choose_table(ix, a1, a2, bi);
        bits = bi.bits;
        if (r01_bits[r0 + r1] > bits) {
          r01_bits[r0 + r1] = bits;
          r01_div[r0 + r1] = r0;
          r0_tbl[r0 + r1] = r0t;
          r1_tbl[r0 + r1] = r1t;
        }
      }
    }
  }

  private void recalc_divide_sub(final LameInternalFlags gfc,
                                 final GrInfo cod_info2, GrInfo gi, final int[] ix,
                                 final int r01_bits[], final int r01_div[], final int r0_tbl[],
                                 final int r1_tbl[]) {
    int bigv = cod_info2.big_values;

    for (int r2 = 2; r2 < Encoder.SBMAX_l + 1; r2++) {
      int a2 = gfc.scalefac_band.l[r2];
      if (a2 >= bigv)
        break;

      int bits = r01_bits[r2 - 2] + cod_info2.count1bits;
      if (gi.part2_3_length <= bits)
        break;

      Bits bi = new Bits(bits);
      int r2t = choose_table(ix, a2, bigv, bi);
      bits = bi.bits;
      if (gi.part2_3_length <= bits)
        continue;

      gi.assign(cod_info2);
      gi.part2_3_length = bits;
      gi.region0_count = r01_div[r2 - 2];
      gi.region1_count = r2 - 2 - r01_div[r2 - 2];
      gi.table_select[0] = r0_tbl[r2 - 2];
      gi.table_select[1] = r1_tbl[r2 - 2];
      gi.table_select[2] = r2t;
    }
  }

  public void best_huffman_divide(final LameInternalFlags gfc,
                                  GrInfo gi) {
    GrInfo cod_info2 = new GrInfo();
    final int[] ix = gi.l3_enc;

    int r01_bits[] = new int[7 + 15 + 1];
    int r01_div[] = new int[7 + 15 + 1];
    int r0_tbl[] = new int[7 + 15 + 1];
    int r1_tbl[] = new int[7 + 15 + 1];

		/* SHORT BLOCK stuff fails for MPEG2 */
    if (gi.block_type == Encoder.SHORT_TYPE && gfc.mode_gr == 1)
      return;

    cod_info2.assign(gi);
    if (gi.block_type == Encoder.NORM_TYPE) {
      recalc_divide_init(gfc, gi, ix, r01_bits, r01_div, r0_tbl, r1_tbl);
      recalc_divide_sub(gfc, cod_info2, gi, ix, r01_bits, r01_div,
          r0_tbl, r1_tbl);
    }

    int i = cod_info2.big_values;
    if (i == 0 || (ix[i - 2] | ix[i - 1]) > 1)
      return;

    i = gi.count1 + 2;
    if (i > 576)
      return;

		/* Determines the number of bits to encode the quadruples. */
    cod_info2.assign(gi);
    cod_info2.count1 = i;
    int a1 = 0;
    int a2 = 0;

    assert (i <= 576);

    for (; i > cod_info2.big_values; i -= 4) {
      final int p = ((ix[i - 4] * 2 + ix[i - 3]) * 2 + ix[i - 2]) * 2
          + ix[i - 1];
      a1 += Tables.t32l[p];
      a2 += Tables.t33l[p];
    }
    cod_info2.big_values = i;

    cod_info2.count1table_select = 0;
    if (a1 > a2) {
      a1 = a2;
      cod_info2.count1table_select = 1;
    }

    cod_info2.count1bits = a1;

    if (cod_info2.block_type == Encoder.NORM_TYPE)
      recalc_divide_sub(gfc, cod_info2, gi, ix, r01_bits, r01_div,
          r0_tbl, r1_tbl);
    else {
			/* Count the number of bits necessary to code the bigvalues region. */
      cod_info2.part2_3_length = a1;
      a1 = gfc.scalefac_band.l[7 + 1];
      if (a1 > i) {
        a1 = i;
      }
      if (a1 > 0) {
        Bits bi = new Bits(cod_info2.part2_3_length);
        cod_info2.table_select[0] = choose_table(ix, 0, a1, bi);
        cod_info2.part2_3_length = bi.bits;
      }
      if (i > a1) {
        Bits bi = new Bits(cod_info2.part2_3_length);
        cod_info2.table_select[1] = choose_table(ix, a1, i, bi);
        cod_info2.part2_3_length = bi.bits;
      }
      if (gi.part2_3_length > cod_info2.part2_3_length)
        gi.assign(cod_info2);
    }
  }

  private void scfsi_calc(int ch, final IIISideInfo l3_side) {
    int sfb;
    final GrInfo gi = l3_side.tt[1][ch];
    final GrInfo g0 = l3_side.tt[0][ch];

    for (int i = 0; i < Tables.scfsi_band.length - 1; i++) {
      for (sfb = Tables.scfsi_band[i]; sfb < Tables.scfsi_band[i + 1]; sfb++) {
        if (g0.scalefac[sfb] != gi.scalefac[sfb]
            && gi.scalefac[sfb] >= 0)
          break;
      }
      if (sfb == Tables.scfsi_band[i + 1]) {
        for (sfb = Tables.scfsi_band[i]; sfb < Tables.scfsi_band[i + 1]; sfb++) {
          gi.scalefac[sfb] = -1;
        }
        l3_side.scfsi[ch][i] = 1;
      }
    }

    int s1 = 0;
    int c1 = 0;
    for (sfb = 0; sfb < 11; sfb++) {
      if (gi.scalefac[sfb] == -1)
        continue;
      c1++;
      if (s1 < gi.scalefac[sfb])
        s1 = gi.scalefac[sfb];
    }

    int s2 = 0;
    int c2 = 0;
    for (; sfb < Encoder.SBPSY_l; sfb++) {
      if (gi.scalefac[sfb] == -1)
        continue;
      c2++;
      if (s2 < gi.scalefac[sfb])
        s2 = gi.scalefac[sfb];
    }

    for (int i = 0; i < 16; i++) {
      if (s1 < slen1_n[i] && s2 < slen2_n[i]) {
        final int c = slen1_tab[i] * c1 + slen2_tab[i] * c2;
        if (gi.part2_length > c) {
          gi.part2_length = c;
          gi.scalefac_compress = i;
        }
      }
    }
  }

  /**
   * Find the optimal way to store the scalefactors. Only call this routine
   * after final scalefactors have been chosen and the channel/granule will
   * not be re-encoded.
   */
  public void best_scalefac_store(final LameInternalFlags gfc, final int gr,
                                  final int ch, final IIISideInfo l3_side) {
		/* use scalefac_scale if we can */
    final GrInfo gi = l3_side.tt[gr][ch];
    int sfb, i, j, l;
    int recalc = 0;

		/*
		 * remove scalefacs from bands with ix=0. This idea comes from the AAC
		 * ISO docs. added mt 3/00
		 */
		/* check if l3_enc=0 */
    j = 0;
    for (sfb = 0; sfb < gi.sfbmax; sfb++) {
      final int width = gi.width[sfb];
      assert (width >= 0);
      j += width;
      for (l = -width; l < 0; l++) {
        if (gi.l3_enc[l + j] != 0)
          break;
      }
      if (l == 0)
        gi.scalefac[sfb] = recalc = -2; /* anything goes. */
			/*
			 * only best_scalefac_store and calc_scfsi know--and only they
			 * should know--about the magic number -2.
			 */
    }

    if (0 == gi.scalefac_scale && 0 == gi.preflag) {
      int s = 0;
      for (sfb = 0; sfb < gi.sfbmax; sfb++)
        if (gi.scalefac[sfb] > 0)
          s |= gi.scalefac[sfb];

      if (0 == (s & 1) && s != 0) {
        for (sfb = 0; sfb < gi.sfbmax; sfb++)
          if (gi.scalefac[sfb] > 0)
            gi.scalefac[sfb] >>= 1;

        gi.scalefac_scale = recalc = 1;
      }
    }

    if (0 == gi.preflag && gi.block_type != Encoder.SHORT_TYPE
        && gfc.mode_gr == 2) {
      for (sfb = 11; sfb < Encoder.SBPSY_l; sfb++)
        if (gi.scalefac[sfb] < qupvt.pretab[sfb]
            && gi.scalefac[sfb] != -2)
          break;
      if (sfb == Encoder.SBPSY_l) {
        for (sfb = 11; sfb < Encoder.SBPSY_l; sfb++)
          if (gi.scalefac[sfb] > 0)
            gi.scalefac[sfb] -= qupvt.pretab[sfb];

        gi.preflag = recalc = 1;
      }
    }

    for (i = 0; i < 4; i++)
      l3_side.scfsi[ch][i] = 0;

    if (gfc.mode_gr == 2 && gr == 1
        && l3_side.tt[0][ch].block_type != Encoder.SHORT_TYPE
        && l3_side.tt[1][ch].block_type != Encoder.SHORT_TYPE) {
      scfsi_calc(ch, l3_side);
      recalc = 0;
    }
    for (sfb = 0; sfb < gi.sfbmax; sfb++) {
      if (gi.scalefac[sfb] == -2) {
        gi.scalefac[sfb] = 0; /* if anything goes, then 0 is a good choice */
      }
    }
    if (recalc != 0) {
      if (gfc.mode_gr == 2) {
        scale_bitcount(gi);
      } else {
        scale_bitcount_lsf(gfc, gi);
      }
    }
  }

  private boolean all_scalefactors_not_negative(final int[] scalefac, int n) {
    for (int i = 0; i < n; ++i) {
      if (scalefac[i] < 0)
        return false;
    }
    return true;
  }

  /**
   * Also calculates the number of bits necessary to code the scalefactors.
   */
  public boolean scale_bitcount(final GrInfo cod_info) {
    int k, sfb, max_slen1 = 0, max_slen2 = 0;

		/* maximum values */
    int[] tab;
    final int[] scalefac = cod_info.scalefac;

    assert (all_scalefactors_not_negative(scalefac, cod_info.sfbmax));

    if (cod_info.block_type == Encoder.SHORT_TYPE) {
      tab = scale_short;
      if (cod_info.mixed_block_flag != 0)
        tab = scale_mixed;
    } else { /* block_type == 1,2,or 3 */
      tab = scale_long;
      if (0 == cod_info.preflag) {
        for (sfb = 11; sfb < Encoder.SBPSY_l; sfb++)
          if (scalefac[sfb] < qupvt.pretab[sfb])
            break;

        if (sfb == Encoder.SBPSY_l) {
          cod_info.preflag = 1;
          for (sfb = 11; sfb < Encoder.SBPSY_l; sfb++)
            scalefac[sfb] -= qupvt.pretab[sfb];
        }
      }
    }

    for (sfb = 0; sfb < cod_info.sfbdivide; sfb++)
      if (max_slen1 < scalefac[sfb])
        max_slen1 = scalefac[sfb];

    for (; sfb < cod_info.sfbmax; sfb++)
      if (max_slen2 < scalefac[sfb])
        max_slen2 = scalefac[sfb];

		/*
		 * from Takehiro TOMINAGA <tominaga@isoternet.org> 10/99 loop over *all*
		 * posible values of scalefac_compress to find the one which uses the
		 * smallest number of bits. ISO would stop at first valid index
		 */
    cod_info.part2_length = QuantizePVT.LARGE_BITS;
    for (k = 0; k < 16; k++) {
      if (max_slen1 < slen1_n[k] && max_slen2 < slen2_n[k]
          && cod_info.part2_length > tab[k]) {
        cod_info.part2_length = tab[k];
        cod_info.scalefac_compress = k;
      }
    }
    return cod_info.part2_length == QuantizePVT.LARGE_BITS;
  }

  /**
   * Also counts the number of bits to encode the scalefacs but for MPEG 2
   * Lower sampling frequencies (24, 22.05 and 16 kHz.)
   * <p/>
   * This is reverse-engineered from section 2.4.3.2 of the MPEG2 IS,
   * "Audio Decoding Layer III"
   */
  public boolean scale_bitcount_lsf(final LameInternalFlags gfc,
                                    final GrInfo cod_info) {
    int table_number, row_in_table, partition, nr_sfb, window;
    boolean over;
    int i, sfb, max_sfac[] = new int[4];
    final int[] partition_table;
    final int[] scalefac = cod_info.scalefac;

		/*
		 * Set partition table. Note that should try to use table one, but do
		 * not yet...
		 */
    if (cod_info.preflag != 0)
      table_number = 2;
    else
      table_number = 0;

    for (i = 0; i < 4; i++)
      max_sfac[i] = 0;

    if (cod_info.block_type == Encoder.SHORT_TYPE) {
      row_in_table = 1;
      partition_table = qupvt.nr_of_sfb_block[table_number][row_in_table];
      for (sfb = 0, partition = 0; partition < 4; partition++) {
        nr_sfb = partition_table[partition] / 3;
        for (i = 0; i < nr_sfb; i++, sfb++)
          for (window = 0; window < 3; window++)
            if (scalefac[sfb * 3 + window] > max_sfac[partition])
              max_sfac[partition] = scalefac[sfb * 3 + window];
      }
    } else {
      row_in_table = 0;
      partition_table = qupvt.nr_of_sfb_block[table_number][row_in_table];
      for (sfb = 0, partition = 0; partition < 4; partition++) {
        nr_sfb = partition_table[partition];
        for (i = 0; i < nr_sfb; i++, sfb++)
          if (scalefac[sfb] > max_sfac[partition])
            max_sfac[partition] = scalefac[sfb];
      }
    }

    for (over = false, partition = 0; partition < 4; partition++) {
      if (max_sfac[partition] > max_range_sfac_tab[table_number][partition])
        over = true;
    }
    if (!over) {

      int slen1, slen2, slen3, slen4;

      cod_info.sfb_partition_table = qupvt.nr_of_sfb_block[table_number][row_in_table];
      for (partition = 0; partition < 4; partition++)
        cod_info.slen[partition] = log2tab[max_sfac[partition]];

			/* set scalefac_compress */
      slen1 = cod_info.slen[0];
      slen2 = cod_info.slen[1];
      slen3 = cod_info.slen[2];
      slen4 = cod_info.slen[3];

      switch (table_number) {
        case 0:
          cod_info.scalefac_compress = (((slen1 * 5) + slen2) << 4)
              + (slen3 << 2) + slen4;
          break;

        case 1:
          cod_info.scalefac_compress = 400 + (((slen1 * 5) + slen2) << 2)
              + slen3;
          break;

        case 2:
          cod_info.scalefac_compress = 500 + (slen1 * 3) + slen2;
          break;

        default:
          System.err.printf("intensity stereo not implemented yet\n");
          break;
      }
    }
    if (!over) {
      assert (cod_info.sfb_partition_table != null);
      cod_info.part2_length = 0;
      for (partition = 0; partition < 4; partition++)
        cod_info.part2_length += cod_info.slen[partition]
            * cod_info.sfb_partition_table[partition];
    }
    return over;
  }

  public void huffman_init(final LameInternalFlags gfc) {
    for (int i = 2; i <= 576; i += 2) {
      int scfb_anz = 0, bv_index;
      while (gfc.scalefac_band.l[++scfb_anz] < i)
        ;

      bv_index = subdv_table[scfb_anz][0]; // .region0_count
      while (gfc.scalefac_band.l[bv_index + 1] > i)
        bv_index--;

      if (bv_index < 0) {
				/*
				 * this is an indication that everything is going to be encoded
				 * as region0: bigvalues < region0 < region1 so lets set
				 * region0, region1 to some value larger than bigvalues
				 */
        bv_index = subdv_table[scfb_anz][0]; // .region0_count
      }

      gfc.bv_scf[i - 2] = bv_index;

      bv_index = subdv_table[scfb_anz][1]; // .region1_count
      while (gfc.scalefac_band.l[bv_index + gfc.bv_scf[i - 2] + 2] > i)
        bv_index--;

      if (bv_index < 0) {
        bv_index = subdv_table[scfb_anz][1]; // .region1_count
      }

      gfc.bv_scf[i - 1] = bv_index;
    }
  }

  static class Bits {
    int bits;

    public Bits(int b) {
      bits = b;
    }
  }
}
